Gas turbine



March 13, 1962 cs oM 3,025,037

GAS TURBINE 2 SheetsSheet 1 In 1/60 for mv/ffz m;

March 3, 1962 B. F. BECKSTROM 3,025,037

GAS TURBINE Filed Oct. 24. 1957 2 Sheets-Sheet 2 y en for 7 ilnited States Patent 3,0Z5,fl37 Patented Pillar. 13, 1962 thee 3,025,037 GAS TURBINE Bert F. Beckstrom, 42M Colfax Ave. 5., Minneapolis, Minn. Fiied Get. 24, 1957, Ser. No. 692,113 2 Claims. (Cl. 253-69) This invention relates to turbines driven by hot expanding gases, and more particularly relates to the blade construction and assembly of such turbines.

An object of my invention is to provide a new and improved gas turbine blade assembly of relatively simple and inexpensive construction and operation.

Another object of my invention is the provision of a novel turbine blade assembly wherein the ceramic blades, in individual annular units, are held together by peripherally extending metal bands.

A further object of my invention is to provide a gas turbine blade assembly wherein the ceramic blade mountings, which may be formed integrally of the blades, provide heat insulation between the blades, over which extremely high temperature gases pass, and the surrounding metallic binding for the blades, and further provides an inertia mass to give the turbine a flywheel effect.

These and other objects and advantages of my invention will more fully appear from the following description made in connection with the accompanying drawings wherein like reference characters refer to the same or similar parts throughout the several views and in which:

FIG. I is a longitudinal section through one side of the gas turbine which is symmetrical around the center line thereof;

FIG. II is a transverse section through one quadrant of the circular gas turbine and being taken along a broken line as indicated at II--II of FIG. 1;

FIG. III is an elevation view of one of the rotor blades and also showing a detail portion of the metallic binder for holding the annular rotor unit together;

FIG. IV is a detail elevation view of one of the blades employed in a stator unit and having a portion broken away to show in section the shape of the blade;

FIG. V is a detail end elevation view of one of the rotor blades as seen in FIG. III and being shown in inverted position with respect to FIG. III;

FIG. VI is an isometric view of one of the rotor blades;

FIG. VII is a detail isometric view showing a modified form of the outer end of one of the rotor blades and a detail portion of the encompassing binder;

FIG. VIII is a detail section view of the rotor with a modified blade; and

FIG. IX is a sectional view taken on the line IX-IX of FIG. IV.

The present invention comprising a gas turbine utilizes ceramic rotor and stator blades which have the ability to withstand extremely high temperatures.

The gas turbine includes a housing H Which is generally cylindrically shaped for confining the stator and rotor units therein. The rotor units each include a plurality of radially extending and inwardly tapering rotor blades 1 which are assembled into annular rotor units or banks and then are assembled in stacked relation with each other and in cooperating relation with the stator units. The rotor blades are provided with enlarged mounting blocks 1:: at the outer ends thereof which, when the blades are assembled into an annular rotor, form a continuous heat insulating periphery between the central blade portions and the outer periphery of the rotor. The outer end of each of the blocks la has a groove 2A formed therein to form, when the blades are assembled, a continuous groove around the outer periphery of the rotor. Each of the blocks 1a has a transverse groove or recess 3 formed in intersecting relation with the groove 2A. Each of the blocks la has, on the opposite sides thereof, male and female deformities 4 and 5 which comprise a projection and a recess and which are formed to interfit with corresponding projections and recesses of adjacent blocks so as to maintain the blades in planar relationship with respect to each other when assembled into a rotor unit. It should be understood that the blade portions are of generally conventional cross-sectional configuration as is indicated by the number 6.

The inner ends of each of the rotor blades are also provided with mounting blocks 1b which also have the projections 4 and recesses 5 therein for interfitting with corresponding parts of adjacent blades.

The stator units are made up from a plurality of generally radially extending and generally inwardly tapering stator blades 7 which are also provided with the mounting blocks 7a and "7b on the inner and outer ends thereof respectively, and having the interfitting projections 4 and recesses 5 for maintaining the stator blades in planar relationship. The stator blades have the conventional shape indicated by the numeral 6.

Each of the rotor and stator units has a metallic binding extending around the outer periphery thereof to hold the stator and rotor blades together in the annular units without causing or permitting any tensile forces to tend to pull the blades apart. The metal binding 8 comprises, in this form of the invention, a plurality of turns of strands of wire of any suitable type resistive to high temperatures. It should be noted, however, that the assembled blocks 1a of the blades provide an annular heat barrier between the high temperature gases and the metallic binding so as to prevent the binding from being subjected to exceedingly high temperatures. In the rotor units, the binder extends through the groove 2A, and in the stator units, the binder will extend through a similar peripherally extending groove 8A. It will therefore be seen that the binder exerts such forces against the blades as to cause only compressive stresses to be set up in the ceramic blades and it will be remembered that ceramic materials have high compressive strengths.

The outer peripheries of the stator units are of uniform diameter and are cooperatively interfitable into the housing 11. Means are provided for maintaining the stator units in alignment, and in the form shown, each of the stator units has, in certain of the outer mounting blocks of the blades, a plurality of slots or grooves for alignment with similar slots or grooves 9 of other stator units. A plurality of bars or guides 19 are afiixed as by welding to the inner side of the housing, and when the stator units are assembled therewith, the guides 10 extend into the grooves 9. Also similarly non-rotatably mounted. in the housing H are a nozzle ring 12 for receiving the hot gases and an exhaust unit having the exhaust port 13 therein communicating with the port 11a in the housing. The nozzle ring is disposed at one end of the stack of stator units and the exhaust unit is disposed at the other end or" the stator units. The nozzle ring is urged and retained in an axial direction in the housing H by a flat clamping ring 14 and a clamping device 15 which is secured as by a bolt to a lug or post on the exterior of the housing H.

A cylindrical ceramic spacer 16 is mounted inwardly of the exhaust unit to provide a heat barrier which reduces the heat which may be radiated inwardly. The ceramic spacer 16 is rotatable with respect to the hollow shaft 17 upon which the rotor units are splined as at 18. The splined relation between the rotor units and the shaft facilitates pre-assembly of the rotor blades into the annular rotor units and then assembly onto the shaft by moving the rotor units longitudinally along the shaft in stacked relation with each other and intermeshed relation with the stator units. The last rotor unit will be engaged by a washer 2i) and be retained on the shaft by a nut 19. The hollow shaft 17 may have an air tube extending therethrough for cooling the shaft.

A fire chamber unit 22 will also be mounted within the housing H adjacent the nozzle ring 12.

As best seen in FIG. 6, the rotor blades have side surfaces 23 which when the blades are assembled into the rotor units, lie in a common plane and confront similar planar surfaces of the stator units in closely spaced relation so as to prevent losses of substantial quantities of heat in this direction.

As best seen in FIG. 5, a band or wrapper 2B is provided in each of the transverse grooves 3 and the ends of the band 213 are cut to such a length as to balance the rotor unit. The bands 23 are wrapped around the multiplicity of strands of Wire in the binder 8 and are welded in this closed position so as to hold the strands of wire together and to prevent any possible peripheral movement of the binder 8 with respect to the rotor unit.

In the form of the invention shown in FIGS. 7 and 8, the binder for securing the rotor blades together, whereby to to form the rotor unit, is in the form of a continuous metal strip 24 extending around the entire periphery of the rotor unit and secured thereto by a plurality of trans verse wrappers or bands which maintain the binder 24 in slightly spaced relation with the ends of the blades, the space being indicated by the numeral 26. The wrappers or bands are mounted in the grooves 27 of each of the blades and each of the bands 25 has a wedge-shaped inner end cooperating with the wedged-shaped inner end of another band in the groove for urging the strip 24 outwardly, or for urging the rotor blade inwardly. The outer ends of the bands are wrapped around the strip 24 and are welded thereto as at 28. Before the outer ends of the bands are closed, the same are cut to such lengths as to balance the rotor unit and will be cut when disposed in the outwardly extending position indicated by the numeral 29.

It will therefore be seen that I have provided a new and improved turbine which may be driven by hot gases and may be made in such sizes as to be suitable for use in automobiles and the like and wherein the rotor and stator units are made up of. blades constructed of ceramic material and are assembled in such a manner that only compressive stresses are set up in the high speeds which are utilized in gas turbines. The rotor units are provided with heat barriers at the outer peripheries thereof to prevent the metallic bindings to be subjected to high temperatures. Because of the weight of the heat insulating peripheral barrier, this barrier will also have a flywheel etfeot. It should be understood that the flywheel effect may be easily changed by increasing or decreasing the size of the heat barrier. Furthermore, the stator and rotor units may be preassembled and then assembled as units into the housing and onto the shaft.

It will, of course, be understood that various changes may be made in the form, detail, arrangement and proportion of the parts without departing from the scope of my invention which consists of the matter described herein and set forth in the appended claims.

What is claimed is:

1. A turbine rotor comprising, a rotary shaft, a rotor unit secured to the shaft, said rotor unit including a plurality of ceramic radial blades having enlarged blocks at the outer ends thereof engaging the blocks of adjacent blades and defining a substantially continuous outer periphery of the rotor unit, the outer periphery of the rotor unit having a peripheral groove therein and each of the blocks having a transverse groove intersecting the periphe'ral groove, a flat and continuous metallic binder strip around the periphery of each rotor unit, a plurality of pairs of balancing bands, the bands in each pair of bands having oppositely arranged wedge-shaped inner ends in wedging relation with the inner end of the other band in the pair and between the rotor periphery and the binder strip for tightening the strip on the rotor, and each band having outer ends of such lengths as to balance the rotor, the outer ends of said balancing bands being secured to the strip for holding the same in clamping relation with the outer periphery of the rotor unit.

2. A gas turbine comprising a housing, a plurality of annular banks of ceramic stator blades in stacked relation with each other along the rotation axis, and the blades in adjacent banks progressively varying in length from one end of the stack to the other, the stator blades each having inner and outer mounting blocks respectively disposed at the inner and outer ends of the blades, the inner and outer mounting blocks of the stator blades each engaging the corresponding blocks of the next adjacent blades in the corresponding annular bank, and the outer blocks of the stator blades engaging the corresponding blocks of the blades in the next adjacent annular banks, the outer blocks of said stator blades being recessed at the inner sides thereof to define annular recesses between each of the annular banks in the stack, means securing the blades together in each of the annular banks, means retaining said annular banks of stator blades in the housing against rotary movement and against movement longitudinally of the rotation axis, a rotor shaft, means journalling the shaft in the housing, a plurality of banks of ceramic rotor blades in stacked relation with each other along the rotation axis, each of said banks of rotor blades being disposed between a pair of banks of stator blades in the stack and the rotor blades progressively varying in length corresponding to the length of the adjacent stator blades, each of said rotor blades having inner and outer blocks formed integrally thereof and engaging the corresponding inner and outer blocks of the adjacent blades in the bank, the outer blocks of said rotor blades being disposed in said annular recesses of the stator banks and each of said annular banks having a metallic binder around the outer periphery of said outer blocks and in said annular recess holding the rotor bank of blades together, the inner blocks of the rotor blades each engaging the inner block of the next adjacent rotor blade in the corresponding bank and also engaging the corresponding block of the rotor blade in the next adjacent bank of rotor blades, and said inner blocks of the rotor blades being recessed in an outward direction to define outwardly facing annular recesses between the adjacent banks of rotor blades and receiving the inner blocks of the stator blades, means non-rotatably securing the banks of rotor blades to the rotor shaft, the inner and outer blocks of said stator and rotor blades cooperating to define inner and outer heat-insulating barriers at the corresponding inner and outer ends of said blades, and said blocks also defining substantially smoothsurfaced walls at the ends of said blades, along which the gas will pass as the gas passes over the blades.

References Cited in the file of this patent UNITED STATES PATENTS 901,459 MacDonald Oct. 20, 1908 1,371,328 Schneider Mar. 15, 1921 1,440,209 Church Dec. 26, 1922 2,155,231 Hubbard et al Apr. 18, 1939 2,308,233 Schutte Jan. 12, 1943 (Other references on following page) Schutte Feb. 15, 1944 Phelan et a1 Nov. 4, 1947 Boestad June 7, 1949 Soderberg Feb. 7, 1950 Bloomberg Mar. 14, 1950 Schorner Aug. 17, 1954 Schorner Aug. 9, 1955 Barrett Nov. 22, 1955 Scharf Jan. 3, 1956 Terrell July 30, 1957 FOREIGN PATENTS Great Britain 1905 Germany Nov. 5, 1910 Germany Nov. 30, 1934 France Sept. 15, 1930 France Dec. 13, 1950 (Addition to No. 907,509) France Sept. 12, 1951 France June 23, 1950 

